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Old 26th October 2009, 17:28   #61
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Default Speed sensing LSD

In any open differential you have the input pinion gear that on one end connects to the prop shaft from the gearbox and on the other end drives a crown wheel. The ratio of pinion to crown wheel is the axle ratio. It is arrived at by dividing the number of teeth on the crown by the number of teeth on the input pinion gear. So a 5.38:1 ratio on the petrol Jeep means 43 teeth on the crown and 8 on the pinion. It also translates into for every 5.38 revs of the prop shaft from the gearbox the wheel rotates once. Invariably you have some torque amplification due to this.

The Crown wheel in turn is bolted onto a cage which contains a set of 4 planetary spider gears. Two of these gears, called pinion gears, spool freely on shafts attached to the cage and the other two known as side gears attach to the axle half shafts. All four spider gears mesh together with each gear in mesh with two others.

When the car is moving in a straight line the pinion gears of the cage are stationary and fuse with the side gears to form a solid block and the entire cage rotates along with both driveshafts.

On a turn the shaft that needs to rotate faster does so by spooling around the slower shaft by way of these four spider gears rotating. The way its designed the number of turns of the crown wheel is equal to the average of the sum of the number of turns of the individual half shafts. So if the crown turns 6 times and the car is turning, one half shaft may rotate 8 times and the other 4 times. This allows the inner wheel to travel slowly while the outer travels faster.

Now on a very slippery condition where one wheel is spinning and the other is stationery the crown rotates at say 6 revs and the spinning wheel rotates at 12 and the other wheel at zero.

In a speed sensing LSD this differential rate of spin of the half shafts trigger an action in a spring pack that in turn pushes the side gears through clutches to lock against the cage forming a solid (almost) unit. When the side gears get locked to the cage both wheels rotate at almost the same speed moving the car out of a slippery condition. This spring and clutch pack LSD is probably the most widely used.

PS pls move to relevant thread

Last edited by DKG : 26th October 2009 at 17:36.
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Old 4th November 2009, 03:14   #62
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Haven't posted here for a while but good to see the ever growing spirit.

The idea suggested below is surely practical and I have seen it being used on all the club trucks here.

It's called fiddle brakes and they give the ability to lock up a wheel, which enables much better spot turning, better control descending hills, traction control by slowing or locking the spinning wheel.

The ones used here are operated by the co-driver. Most trucks have four individual ones and keeps the co driver active than hanging on to a dead bar
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Old 4th November 2009, 09:55   #63
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Quote:
Originally Posted by Motocoorg View Post
It's called fiddle brakes and they give the ability to lock up a wheel, which enables much better spot turning, better control descending hills, traction control by slowing or locking the spinning wheel.

The ones used here are operated by the co-driver. Most trucks have four individual ones and keeps the co driver active than hanging on to a dead bar
Very interesting to know its a feature actually used by some offroaders !! My truck handbrake has a junction where from the single cable splits to two for the rear wheels. I think if I add the two levers at that point then I have individual braking available.
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Old 4th November 2009, 09:57   #64
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I think tempo traveller(older one) had this fiddle brake thingy
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Old 11th March 2010, 17:41   #65
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Eaton Corp is launching its products in India. A mechanical (for trucks) and electric locker starting with the Indica and Punto
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Old 11th March 2010, 17:54   #66
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Originally Posted by DKG View Post
Eaton Corp is launching its products in India. A mechanical (for trucks) and electric locker starting with the Indica and Punto
Differential Locks for the Indica?
Who would need it?
Btw, Why would anyone need diff locks for the Punto as well?
I'll agree that an LSD for the Punto would make good sense though.
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Old 11th March 2010, 20:11   #67
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Quote:
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Eaton Corp is launching its products in India. A mechanical (for trucks) and electric locker starting with the Indica and Punto
I think eaton has some collaboration with Mahindra as well. Is there any info regarding LSD/lockers for Jeeps / Gypsies?
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Old 11th March 2010, 22:52   #68
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Quote:
Originally Posted by nitrous View Post
Differential Locks for the Indica?
Who would need it?
Btw, Why would anyone need diff locks for the Punto as well?
I'll agree that an LSD for the Punto would make good sense though.
Check out the article in this month's Car India

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I think eaton has some collaboration with Mahindra as well. Is there any info regarding LSD/lockers for Jeeps / Gypsies?
Its apparently a matter of time before they launch more products
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Old 13th March 2010, 12:24   #69
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Quote:
Originally Posted by DKG View Post
Eaton Corp is launching its products in India. A mechanical (for trucks) and electric locker starting with the Indica and Punto
Quote:
Originally Posted by nitrous View Post
Differential Locks for the Indica?
Who would need it?
Btw, Why would anyone need diff locks for the Punto as well?
I'll agree that an LSD for the Punto would make good sense though.
Quote:
Originally Posted by DKG View Post
Check out the article in this month's Car India
Can you post it here. Maybe they are coming out with some kind of LSD but market it as a Diff LOCK!!

LSD in a FWD car aids better control as well as traction!
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Old 14th March 2010, 20:43   #70
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Did any of the old army Jeeps come with Diff locks ? I vaguely remember one of army drivers mentioning about this... not sure tho...
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Old 11th April 2010, 16:04   #71
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Default Independent Hand Brakes over Lockers

So Arka, what has your experience been after trying this? You felt the brakes were not powerful enough to ensure the torque was transferred to the other wheel?

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Originally Posted by ex670c View Post
It is a simple mechanical mod, which we have tried out on a JEEP (rear axle) inspired by M&M Tractors.

Personally I prefer being mechanically inclined in the head and hands on.

Absolutely agree with the second point, its called "Tread Lightly"

However maximum trail damage is caused by unprepared/2WD trail vehicles, as they spin their wheels at every obstacle.

Regards,

Arka
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Old 12th April 2010, 12:43   #72
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Default Cutting/Fiddle Brakes

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Originally Posted by Red Liner View Post
So Arka, what has your experience been after trying this? You felt the brakes were not powerful enough to ensure the torque was transferred to the other wheel?
Hi Venkat,

The Experience was good as were looked into M&M Rear Axle Handbrake systems, but it did not solve the purpose.

The Cable Actuated system is not very reliable and the Brakes don't lockup or release as fast as we would.

Actually you get a very effective hand brake system though

Off-Roader on a budget in USA & Europe use Cutting Brakes/Fiddle Brakes similar setup Hydraulically actuated with Booster Assisted Drums or Disc Brakes.

Regards,

Arka
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Old 12th April 2010, 21:43   #73
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Default Cutting Brakes/Fiddle Brakes: Poor Man's Diff locks

Looking at all the trouble with Diff-Locks and LSD's, this seems like a very good compromise...like the poor man's diff locks.

Maybe I should give this a shot. Will ring you to discuss sometime when you are not away at the Palar Recce's :-)

Quote:
Originally Posted by ex670c View Post
Hi Venkat,

The Experience was good as were looked into M&M Rear Axle Handbrake systems, but it did not solve the purpose.

The Cable Actuated system is not very reliable and the Brakes don't lockup or release as fast as we would.

Actually you get a very effective hand brake system though

Off-Roader on a budget in USA & Europe use Cutting Brakes/Fiddle Brakes similar setup Hydraulically actuated with Booster Assisted Drums or Disc Brakes.

Regards,

Arka
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Old 1st July 2010, 07:10   #74
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Default Lockers For Mahindra Jeeps

Hi all,
everyone please share information about which type of lockers will be the best for our Mahindra jeeps, did some research some which are available will not fit properly due to spline count in our Indian Jeeps .we use Dana 44 but it seems the spline count is different. Has anyone fitted Lockers , Please share thanks.
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Old 1st July 2010, 14:39   #75
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Hi Rahul,

You can read more about Lockers/LSD/Traction-aiding devices for Jeep here.

http://www.team-bhp.com/forum/4x4-te...ks-vs-lsd.html (Diff-Locks vs LSD)

(Mods, please merge 2)

Does your MM440 have a 19 spline axle? or a 30? Dana 44 indicates the differential type and not the spline count. There are lockers/LSD's available for both 19 & 30 count D-44 type diffs. 3 Jeepers from bangalore (that I know of) have Lockers in their machines. Me, prabhuav and rajeshnarayanan. Many Gypsy'ers also have got lockers...

Note - Mostly likely source of such parts are USA only. My jeep (CJ340) has a 19spl,D44 setup. I got Richmond LockRight Locker for ~350$ (~16,000Rs).

More here.
http://www.team-bhp.com/forum/1898793-post155.html

Let me know if you need any help in getting these parts over from USA... I will try to help you.
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